2011 Range Rover Sport HSE 85,000 miles. Navigation screen is black and in dash cd player will not accept disk. Vehicle runs and drives perfectly. OBD code UO184 which is lost communication with radio. First day of problem the screen briefly flashed the Land Rover start up logo a few times. All fuses check out ok. Pulled nav screen unit and cd/nav unit, checked connections at dash. No radio. Android phone connects to radio via bluetooth, but no bluetooth connection to vehicle phone. No response so far, assuming a short or ground fault, or bad cd/nav unit due to not accepting disk and lost OBD connection error. Any thoughts prior to taking in for service $$$$$ would be appreciated.